Antalya is unusual among Mediterranean resort cities in having its airport almost inside town. The centre is 22 km from the terminal and our median across 79 completed transfers is 29 minutes.
The recorded distances spread from 17 to 26 km, and that spread is the city itself rather than the road. Kaleici and the old harbour sit at the near end, Konyaalti and the western beaches at the far end; between them lies the whole downtown.
Kaleici needs a word of its own. The walled old town is a grid of narrow lanes behind gates, and most of it is closed to vehicles. The driver stops at the nearest gate and walks you in with the luggage. Which gate depends on the hotel, which is why the hotel name matters more here than anywhere else in Antalya.
On a run this short, waiting costs more than driving. The pickup is timed to your actual landing rather than the schedule, and the driver is in arrivals before the belt starts.